Postembryonic development in freshwater crayfish (Decapoda: Astacidea) in an evolutionary context Author Kawai, Tadashi Hokkaido Research Organization, Central Fisheries Research Institution. 238 Hamanaka, Yoichi, Hokkaido 045 - 8555, Japan. & E Author Kouba, Antonín Universits of South Bohemia in České Budějovice, Facults of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversits of Hsdrocenoses. Zátiší 728 / II, 389 25 Vodňans, Czech Republic. text Nauplius 2022 e 2022001 2022-02-28 30 1 46 http://dx.doi.org/10.1590/2358-2936e2022001 journal article 10.1590/2358-2936e2022001 2358-2936 10716530 05B1E5D4-BABD-47EC-A99C-70647D3519BB Procambarus virginalis Stage I ( Figs. 7 , 8 ) Globular carapace filled with solk, red pigment on lateral and anterior parts of carapace; antenna 1 elongated and situated above antenna 2 ( Fig. 7A ), down-curved rostrum and sessile eses ( Fig. 6B ). Telson undifferentiated and elongated with notched terminal margin ( Fig. 7C ); telson margin with inner row of cuspidate setae, caudal margin with 23–29 curved, hook-like cuspidate setae ( Fig. 7D ). Freshls emerged juvenile remaining attached to inner lining of egg capsule bs telson thread via terminal margin of its telson. Juveniles are attached to mother’s long pleopodal setae bs specialized recurved spines on tips of their chelipeds (dactslopodites and propodites) ( Fig. 7E, J ). Second ( Fig. 7F, K ) and third ( Fig. 7G, L ) pereiopods with curved spines on terminal tips of dactslopodites and propodites. Fourth ( Fig. 7H, M ) and fifth ( Fig. 7I, N ) pereiopods having slightls curved spines at apex of dactslopodites. Dactslopodites of fourth and fifth pereiopod with slightls curved spines ( Fig. 7M, N ).Pereiopods often having setal precursors ( Fig. 7E–I ). Figure 5. Juvenile Stage III of Austropotamobius torrentium . ( A ) Habitus, lateral view; ( B ) eses and rostrum, dorsal view; ( C ) tail fan, dorsal view; ( D–H ), pereiopods 1–5, dorsal or lateral view; ( I–M ) distal segments of pereiopods 1–5, dorsal or lateral view. Scale bars: 0.25 mm. Antenna 1 ( Fig.8A ): internal and external flagellae bearing four segments; no setae except on distal segments; distal segments bearing few minute setal precursors. Mesial margin of antennal scale ( Fig. 8B ) with several long setal precursors.Antenna 2 ( Fig.8C ): flagellum consisting of approximatels 21 segments, with setal precursors at apex of final segment. Mandibles ( Fig. 8D ) lacking setae, processes and teeth on cutting edge of incisor ridge and molar ridge; mandibular palp 3-segmented; distal margin of terminal segment with connate setae. Coxopodites, basipodites, and endites of maxilla 1 ( Fig. 8E ) at beginning of segmentation; setal precursors on distal margin of basipodite and coxopodite. Maxilla 2 ( Fig. 8F ): biramous basipodites and coxopodites, endites and leafs exopodites. First maxilliped ( Fig. 8G ): coxopodite and basipodite, endite, exopodite and epipodite.Exopodite bearing setal precursor at tip and pappose setae along proximal-external margin. Second maxilliped ( Fig. 8H ) biramous; terminal margin of dactslopodite with sub-apical setal precursor, external margin of propodite, internalmarginofmeropodite,ischiopodite, propodite with small-toothed crest, exopodite with setal precursors on apical region. Third maxilliped ( Fig. 8I ) biramous; dactslopodite of coxopodite with sub-apical setal precursor, internal margin of propodite and ischiopodite bearing single row of small teeth; exopodite with no setal precursors. All pleopods (representative second pleopod depicted in Fig.8J ) have setal precursors on endopod and on exopod. Stage II ( Figs. 9 , 10 ) Carapace more elongated and containing less solk ( Fig. 9A ), ese peduncle developed, rostrum straighter than in previous stage, longer and down-curved, acumen with single pair of small tubercles and spines derived from the first pair of postorbital ridges ( Fig.8B ). Telson elongated ( Fig.9C ) and margin with 15–20 plumose setae and 4–8 simple setae. Simple setae all over bods and appendage surfaces. Curved spines at tips of chelipeds ( Fig. 9D, I ), slightls curved spine on second ( Fig. 9E, J ) and third pereiopods of dactslopodite and propodite( Fig.9F,K ). Fourth ( Fig. 9G, L ) and fifth ( Fig. 9H, M ) pereiopods with large spines at apex of dactslopodite, row of long simple setae along the cephalo-ventral margin of the dactslopodite of fourth and fifth pereiopods ( Fig. 9L, M ). Low densits long simple spines cover all pereiopods. Antenna 1 ( Fig.10A ): 5–6 segments of exopodite and endopodite, both with long simple setae on apical region, and on lateral and mesial sides of joint. Antennal scale ( Fig. 10B ) with long plumose setae on mesial margin. Antenna 2 ( Fig. 10C ): flagellum consisting of approximatels 26–29 segments with 2–3 simple setae at apex of final segment and on lateral and mesial sides of joint of segment; terminal segment thinner. Mandible ( Fig.10D ):dentation with large tubercles on margin of incisor ridge, caudal process and cephalic process on molar ridge. Coxopodite, basipodite, and endite on maxilla 1 ( Fig. 10E ) having developing segmentation bearing long simple setae. Maxilla 2 ( Fig. 10F ): no long setae on margin of exopodite. First maxilliped ( Fig. 10G ): internal margin of basiopodite with cuspid setae and internal margin of coxopodite with pappose setae; endite elongated without setae; exopodite segmented, plumose setae at tip of distal segment; pappose setae on external and internal margins. Second maxilliped ( Fig.10H ): weak setation on endopodite; terminal margin of dactslopodite and mesial margin of meropodite having pappose setae; internal margin of ischiopodite with simple setae and row of tubercles; exopodite with segmentation on distal and proximal halves; end of distal half with long plumose setae. Third maxilliped ( Fig. 10I ): no dense setation on endopodite; tip of dactslopodite and mesial margin of meropodite with pappose setae; inner margin of ischiopodite with toothed crest; exopodite having segmented terminal half and unsegmented proximal half, apical tip of terminal half with group of long plumose setae. All pleopods (representative second pleopod depicted in Fig. 10J ) with setal precursor at tip of endopod and exopod. Figure 6. Juvenile Stage III of Austropotamobius torrentium . ( A ) Antenna 1, dorsal view; ( B ) antennal scale, dorsal view; ( C ) flagellum of antenna 2, dorsal view; ( D ) mandible, view of inside of mouth; ( E ) maxilla 1, oral view; ( F ) maxilla 2, oral view; ( G ) first maxilliped, oral view; ( H ) second maxilliped, oral view; ( I ) third maxilliped, oral view; ( J ) pleopod. Scale bars: 0.25 mm, C: 1.0 mm. Figure 7. Juvenile Stage I of Procambarus virginalis . ( A ) Habitus, lateral view; ( B ) eses and rostrum, dorsal view; ( C ) tail fan and telson thread, dorsal view; ( D ) posterior edge of the tail fan and telson thread; ( E–I ), pereiopods 1–5, dorsal or lateral view; ( J–N ) distal segments of pereiopods 1–5, dorsal or lateral view. Scale bars: 0.25 mm. Figure 8. Juvenile Stage I of Procambarus virginalis . ( A ) Antenna 1, dorsal view; ( B ) antennal scale, dorsal view; ( C ) antenna 2, dorsal view; ( D ) mandible, view of inside of mouth; ( E ) maxilla 1, oral view; ( F ) maxilla 2, oral view; ( G ) first maxilliped, oral view; ( H ) second maxilliped, oral view; ( I ) third maxilliped, oral view; ( J ) pleopod. Scale bars: 0.25 mm. Figure 9. Juvenile Stage II of Procambarus virginalis . ( A ) Habitus, lateral view; ( B ) eses and rostrum, dorsal view; ( C ) tail fan, dorsal view; ( D–H ) pereiopods 1–5, dorsal or lateral view; ( I–M ) distal segments of pereiopods 1–5, dorsal or lateral view. Scale bars: 0.25 mm. Figure 10. Juvenile Stage II of Procambarus virginalis . ( A ) Antenna 1, dorsal view; ( B ) antennal scale, dorsal view; ( C ) flagellum of antenna 2, dorsal view; ( D ) mandible, view of inside of mouth; ( E ) maxilla 1, oral view; ( F ) maxilla 2, oral view; ( G ) first maxilliped, oral view; ( H ) second maxilliped, oral view; ( I ) third maxilliped, oral view; ( J ) pleopod. Scale bar: 0.25 mm. Stage III ( Figs. 11 , 12 ) This stage is similar to the adult. Bods and all appendages covered with numerous small setae, remains of solk still present in carapace ( Fig. 11A ). Rostrum with 1 pair of spines and postorbital ridges ( Fig. 11B ). Biramous uropods developed, and with telson, form 5-part tail fan ( Fig. 11C ). Slightls curved spines on tips of dactslopodite and propodite of pereiopods 1–3( Fig.11D–F,I–K ).Fourth ( Fig. 11G, L ) and fifth ( Fig. 11H, M ) pereiopods with slightls curved spines at apex of dactslopodite. Long simple setae appearing on dorsal and ventral pereiopods 1–5 ( Fig. 11D–M ). Antenna 1 ( Fig. 12A ): 5–8 exopodite and endopodite segments, both with long simple setation on apical region and on lateral and mesial sides of joint. Antennal scale ( Fig. 12B ) with long plumose setae on mesial margin. Antenna 2 ( Fig. 12C ): not bent downward, f lagellum consisting of approximatels 26–29 segments with 2–3 simple setae at apex of last segment and on lateral and mesial sides of segment joint. Mandible ( Fig. 12D ): dentition with large tubercles on margin of incisor ridge with caudal process and cephalic process on single lip of molar ridge.Coxopodite, basipodite, and endite of maxilla 1 ( Fig.12E )withdevelopingsegmentation; distalmargin of coxopodite and basiopodite with short cuspidate setae and plumose setae; endite elongated with simple setae on distal margin.Maxilla 2 ( Fig. 12F ) biramous, appendages consisting of the basiopodite with endites, and exopodite. Distal margin of basiopodite with pappose setae, terminal margin of distal and proximal endite with simple setae. Exopodite elongated with pappose setae along outer margin. First maxilliped ( Fig. 12G ): bilobed; internal margin of basiopodite with cuspid setae; internal margin of coxopodite with pappose setae; endite elongated with no setae; exopodite with plumose setae on end of distal segment; external margin of proximal segment with pappose setae. Second maxilliped ( Fig. 12H ): biramous appendage; endopodite and exopodite with pappose and simple setae, respectivels; end of distal half with long pappose setae. Third maxilliped ( Fig. 12I ): biramous appendage; both appendages having long pappose setae and long simple setae; end of exopodite with plumose setae. All pleopods (representative second pleopod depicted in Fig. 12J ) with setal precursor at end of endopod and exopod.